Maintenance information output apparatus and maintenance information output system

ABSTRACT

A maintenance information output system is provided that includes an iron amount detecting device, a receiver, a maintenance information output apparatus, and a controlling portion. The iron amount detecting device is attached to a speed reducer, and detects an amount of iron in a lubricant in the speed reducer. The receiver receives data of the amount of iron detected by the iron amount detecting device. The maintenance information output apparatus has an outputting portion which outputs maintenance information of the speed reducer. The maintenance information output apparatus has a receiving portion which receives the data from the receiver. When the amount of iron is equal to or larger than a threshold value, the controlling portion causes the outputting portion to output the maintenance information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent applicationSer. No. 12/090,926 filed Mar. 6, 2009, which, in turn, is a Section 371of International Application No. PCT/JP2006/320967, filed Oct. 20, 2006,which was published in the Japanese language on Apr. 26, 2007, underInternational Publication No. WO 2007/046505 A1. The entire disclosuresof each of these prior applications are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a maintenance information outputapparatus which outputs maintenance information of a speed reducer usedin an industrial robot, a machine tool, or the like.

2. Background Art

As a conventional maintenance information output apparatus, known is anapparatus in which the life of a speed reducer is calculated andaccumulated at each sampling time from the generated torque, number ofrotations, and accumulated operation time of a servo motor for driving arobot manipulator of an industrial robot, and, when the accumulatedvalue exceeds a predetermined reference value, the need for inspectionor replacement of the speed reducer is displayed (for example, seePatent Reference 1).

Patent Reference 1: JP-A-7-124889 (pages 2 and 3, FIGS. 1 and 2)

DISCLOSURE OF THE INVENTION Problems that the Invention is to Solve

In a conventional maintenance information output apparatus, however,influences on the life of a speed reducer due to causes other than thegenerated torque, number of rotations, and accumulated operation time ofa servo motor, such as those on the life of a speed reducer due to theatmosphere temperature, a lubrication failure in the speed reducer,assembly mismatching, deformation of a member, and the like are notconsidered, and the life of the speed reducer is predicted only on thebasis of the generated torque, number of rotations, and accumulatedoperation time of the servo motor. Therefore, there is a problem in thatmaintenance information of a speed reducer used in an industrial robotis sometimes inadequate.

In a conventional maintenance information output apparatus, for example,there is a case that the need for inspection or replacement of a speedreducer is not displayed in spite that the speed reducer is actually atthe end of the life, or the need for inspection or replacement of aspeed reducer is displayed although the speed reducer is not actually atthe end of the life.

The invention has been conducted in order to solve the problem of theconventional art. It is an object of the invention to provide amaintenance information output apparatus which can output maintenanceinformation of a speed reducer used in an industrial robot, moreadequately than the conventional art.

Means for Solving the Problems

The maintenance information output apparatus of the invention comprises:an outputting portion which outputs maintenance information of a speedreducer; and a controlling portion which, when an amount of iron in alubricant in the speed reducer is equal to or larger than a thresholdvalue, causes the outputting portion to output the maintenanceinformation.

According to the configuration, on the basis of the amount of iron whichis actually produced in the lubricant in the speed reducer as a resultof wear of the speed reducer, the maintenance information outputapparatus of the invention outputs maintenance information of the speedreducer. Therefore, the apparatus can output maintenance information ofthe speed reducer, more adequately than the conventional art.

In the maintenance information output apparatus of the invention,furthermore, the threshold value is disposed in plural steps, and themaintenance information is disposed in plural steps in accordance withthe steps of the threshold value.

According to the configuration, the maintenance information outputapparatus of the invention can allow the user to perform stepwisemaintenance.

The maintenance information output system of the invention wherein thesystem comprises: an iron amount detecting device which is attached to aspeed reducer, and which detects an amount of iron in a lubricant in thespeed reducer; a receiver which receives data of the amount of irondetected by the iron amount detecting device; and a maintenanceinformation output apparatus having an outputting portion which outputsmaintenance information of the speed reducer, and the maintenanceinformation output apparatus has: a receiving portion which receives thedata from the receiver; and a controlling portion which, when the amountof iron is equal to or larger than a threshold value, causes theoutputting portion to output the maintenance information.

According to the configuration, on the basis of the amount of iron whichis actually produced in the lubricant in the speed reducer as a resultof wear of the speed reducer, the maintenance information output systemof the invention outputs maintenance information of the speed reducer.Therefore, the system can output maintenance information of the speedreducer, more adequately than the conventional art.

The maintenance information output method of the invention has aconfiguration in which an amount of iron in a lubricant in a speedreducer is detected, and, when the amount of iron is equal to or largerthan a threshold value, maintenance information of the speed reducer isoutput.

According to the configuration, in the maintenance information outputmethod of the invention, on the basis of the amount of iron which isactually produced in the lubricant in the speed reducer as a result ofwear of the speed reducer, maintenance information of the speed reduceris output. Therefore, the method can output maintenance information ofthe speed reducer, more adequately than the conventional art.

Effect of the Invention

The invention can provide a maintenance information output apparatuswhich can output maintenance information of a speed reducer moreadequately than the prior art.

The eccentric oscillation speed reducer of the invention wherein thespeed reducer comprises: a first member having internal teeth; anexternal tooth member which has external teeth meshing with the internalteeth, which is engaged with a crankshaft, and which eccentricallyoscillates; and a second member which is engaged with the external toothmember, and which is rotatable with respect the first member,

the crankshaft and the external tooth member are housed in a spaceformed by the first member and the second member, and

the speed reducer comprises an iron amount detecting device which isattached to at least one of the first member and the second member, andwhich detects an amount of iron in a lubricant in the space.

According to the configuration, the eccentric oscillation speed reducerof the invention can detect the amount of iron which is actuallyproduced in the lubricant in the speed reducer as a result of wear ofthe speed reducer. On the basis of the detected amount of iron,maintenance information of the speed reducer is output. Therefore,maintenance information of the speed reducer can be output moreadequately than the conventional art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a maintenance information output system of anembodiment of the invention.

FIG. 2A is a section view of an eccentric oscillation speed reducer towhich an iron amount detecting device of the maintenance informationoutput system shown in FIG. 1 is attached.

FIG. 2B is a section view of a portion in the vicinity of the ironamount detecting device in the speed reducer to which the iron amountdetecting device of the maintenance information output system shown inFIG. 1 is attached.

FIG. 3 is a block diagram of the iron amount detecting device of themaintenance information output system shown in FIG. 1.

FIG. 4 is a block diagram of a portable wireless receiver of themaintenance information output system shown in FIG. 1.

FIG. 5 is a block diagram of a maintenance information output apparatusof the maintenance information output system shown in FIG. 1.

FIG. 6 is a view showing a time series change of an amount of iron in alubricant in the speed reducer.

FIG. 7 is a flowchart of a data analysis process of the maintenanceinformation output apparatus shown in FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

Best Mode for Carrying Out the Invention

Hereinafter, an embodiment of the invention will be described withreference to the drawings.

First, the structure of a maintenance information output system of theembodiment will be described.

As shown in FIG. 1, the maintenance information output system 100comprises: iron amount detecting devices 110 (see FIG. 2B) which areattached respectively to plural eccentric oscillation speed reducers 20used in rotation transmitting portions of an industrial robot 10 placedin a production line, and which detect the amount of iron in a lubricant20 a (see FIG. 2B) in the speed reducers 20; a portable wirelessreceiver 120 which wirelessly receives data of the amounts of irondetected by the iron amount detecting devices 110; and a maintenanceinformation output apparatus 130 which is a computer that is placed in amaintenance room separated from the production line, and that outputsmaintenance information of the speed reducers 20.

For example, the eccentric oscillation speed reducer 20 shown in FIG. 2Ais attached to a joint portion of the robot 10, and comprises: aone-side member 12 a which constitutes the joint portion of the robot10; an internal tooth member 21 which is fixed to the one-side member 12a by bolts, and which has internal teeth on the inner circumference; twoexternal tooth members 24 each of which has external teeth meshing withthe internal teeth, and which are engaged with a crankshaft 23 toeccentrically oscillate; a member 12 b which constitutes another side ofthe joint portion of the robot 10; and a support member 22 which isfixed to the other member 12 b by bolts, and which is engaged with thecrankshaft 23 to be relatively rotatable with respect to the internaltooth member 21. In the speed reducer 20, a motor 25 is fixed to theone-side member 12 a to supply a rotational driving force to the speedreducer 20. Namely, the rotation supplied from the motor 25 is input tothe crankshaft 23 through: an input shaft 26 which is housed in thespeed reducer 20; a small gear 26 a which is formed in one end of theinput shaft 26; and a large gear 27 which is fixed to one end of thecrankshaft 23, and which meshes with the small gear 26 a.

In the speed reducer 20, the one-side member 12 a of the joint portionof the robot 10, and the internal tooth member 21 are integrated witheach other to constitute one member of the speed reducer of theinvention, and the member 12 b which constitutes the other side of thejoint portion of the robot 10, and the support member 22 are integratedwith each other to constitute a second member. The first member and thesecond member perform relative rotary motion to function as the jointportion of the robot portion. The crankshaft 23 and the external toothmembers 24 are housed in a space formed by the first member and thesecond member.

The iron amount detecting devices 110 which detect the amount of iron inthe lubricant in the space are attached to the one member 12 a and othermember 12 b that constitute the joint portion of the robot 10.

In the invention, the amount of iron in the lubricant 20 a may be anykind of value as far as it indicates the amount of iron in the lubricant20 a, such as the mass, the concentration, and the like of iron in thelubricant 20 a. The maintenance information of the speed reducers 20means information for performing maintenance on the speed reducer 20,such as information for inspection or replacement of the speed reducer20.

As shown in FIG. 3, the iron amount detecting device 110 comprises: aproximity sensor 111 which detects the amount of iron in the lubricant20 a (see FIG. 2B) in the speed reducer 20 (see FIGS. 1 and 2A); awireless communicating portion 112 which wirelessly communicates with anexternal apparatus; a processing device 113 which is configured by a CPU(Central Processing Unit), a ROM (Read Only Memory), a RAM (RandomAccess Memory), and the like, and which controls the operations of theproximity sensor 111 and the wireless communicating portion 112; and abattery 114 which supplies an electric power to the proximity sensor111, the wireless communicating portion 112, and the processing device113. Preferably, the proximity sensor 111 may be a sensor in which, evenwhen a large number of detections are performed, the detection accuracyis hardly lowered. The battery 114 is preferably placed at a positionwhere replacement of the battery 114 can be easily performed, such as anouter circumferential portion the speed reducer 20.

As shown in FIG. 4, the portable wireless receiver 120 comprises: anoperating portion 121 which is operated by the user; a wirelesscommunicating portion 122 which wirelessly communicates with an externalapparatus; a wired communicating portion 123 which communicates by wirewith an external apparatus; a display 124 which performs variousdisplays; a processing device 125 which is configured by a CPU, a ROM, aRAM, and the like, and which controls the operations of the wirelesscommunicating portion 122, the wired communicating portion 123, and thedisplay 124 in accordance with an operation on the operating portion121; and a power supplying portion 126 which supplies an electric powerto the wireless communicating portion 122, the wired communicatingportion 123, the display 124, and the processing device 125.

As shown in FIG. 5, the maintenance information output apparatus 130comprises: an operating portion 131 which is operated by the user; awired communicating portion 132 which communicates by wire with anexternal apparatus; a hard disk 133 which stores data received by thewired communicating portion 132; a display 134 which performs variousdisplays; a processing device 135 which is configured by a CPU, a ROM, aRAM, and the like, and which controls the operations of the wiredcommunicating portion 132, the hard disk 133, and the display 134 inaccordance with an operation on the operating portion 131; and a powersupplying portion 136 which supplies an electric power to the wiredcommunicating portion 132, the hard disk 133, the display 134, and theprocessing device 135. The wired communicating portion 132 receives dataof the amount of iron from the portable wireless receiver 120 (see FIG.1), and constitutes a receiving portion. The display 134 outputsmaintenance information of the speed reducer 20 (see FIG. 1), andconstitutes an outputting portion. The processing device 135 controlsthe display 134 to output maintenance information of the speed reducer20 when the amount of iron obtained from the portable wireless receiver120 is equal to or larger than a threshold value, and constitutes acontrolling portion. The processing device 135 may operate in accordancewith programs which are previously stored in the ROM, or alternativelyoperate in accordance with programs which are externally obtainedthrough a recording medium or a network.

Next, the operation of the maintenance information output system 100will be described.

First, the operation when the portable wireless receiver 120 obtainsdata of the amounts of iron in the lubricants 20 a in the speed reducers20 from the iron amount detecting devices 110, and stores the data willbe described.

When the user carries the portable wireless receiver 120 to the vicinityof the industrial robot 10 and selects one of the plural speed reducers20 of the industrial robot 10 through the operating portion 121 of theportable wireless receiver 120, the processing device 125 of theportable wireless receiver 120 requests through the wirelesscommunicating portion 122, in the case where the wireless communicatingportion 112 of the iron amount detecting device 110 attached to thespeed reducer 20 which is selected by the user can communicate with thewireless communicating portion 122, the iron amount detecting device 110attached to the speed reducer 20 which is selected by the user, totransmit data of the amount of iron in the lubricant 20 a in the speedreducer 20.

When the iron amount detecting device 110 receives the request fortransmission of the data of the amount of iron in the lubricant 20 a inthe speed reducer 20 from the portable wireless receiver 120 through thewireless communicating portion 112, the processing device 113 of theiron amount detecting device detects the amount of iron in the lubricant20 a in the speed reducer 20 by the proximity sensor 111, and transmitsdata of the detected amount of iron to the portable wireless receiver120 through the wireless communicating portion 112.

When the portable wireless receiver 120 receives the data of the amountof iron transmitted through the wireless communicating portion 122 fromthe wireless communicating portion 112 of the iron amount detectingdevice 110, the processing device 125 of the portable wireless receiverstores the received data of the amount of iron into the RAM, and thendisplays the data on the display 124.

The portable wireless receiver 120 performs an operation similar to thatdescribed above on the plural speed reducers 20, whereby, with respectto each of the plural speed reducers 20, data of the amount of iron inthe lubricant 20 a in the speed reducer 20 can be stored.

Next, the operation when the maintenance information output apparatus130 obtains data of the amounts of iron in the lubricants 20 a in thespeed reducers 20 from the portable wireless receiver 120, and storesthe data will be described.

When the user carries the portable wireless receiver 120 to the vicinityof the maintenance information output apparatus 130, connects theportable wireless receiver 120 with the maintenance information outputapparatus 130 through a communication cable which is not shown, andrequests the maintenance information output apparatus 130 through theoperating portion 131 to obtain the data of the amounts of iron storedin the RAM of the processing device 125 of the portable wirelessreceiver 120, the processing device 135 of the maintenance informationoutput apparatus 130 requests the portable wireless receiver 120 throughthe wired communicating portion 132 to transmit the data of the amountsof iron stored in the RAM of the processing device 125.

When the portable wireless receiver 120 receives the request fortransmission of the data of the amounts of iron stored in the RAM fromthe maintenance information output apparatus 130 through the wiredcommunicating portion 123, the processing device 125 of the portablewireless receiver transmits all the data of the amounts of iron storedin the RAM to the maintenance information output apparatus 130 throughthe wired communicating portion 123.

When the maintenance information output apparatus 130 receives the dataof the amounts of iron transmitted through the wired communicatingportion 132 from the wired communicating portion 123 of the portablewireless receiver 120, the processing device 135 of the maintenanceinformation output apparatus stores the received data of the amount ofiron into the hard disk 133.

Next, with respect to each of the plural speed reducers 20 of theindustrial robot 10, the processing device 135 displays the latest valueof the amounts of iron stored in the hard disk 133, and a time seriessuch as shown in FIG. 6 on the display 134.

Then, with respect to each of the plural speed reducers 20 of theindustrial robot 10, the processing device 135 performs a data analysisprocess shown in FIG. 7.

In the data analysis process shown in FIG. 7, the processing device 135determines whether the latest value of the amounts of iron stored in thehard disk 133 is equal to or larger than a threshold value x₁ (see FIG.6) or not (S151).

If the processing device 135 determines in S151 that the latest value ofthe amounts of iron stored in the hard disk 133 is smaller than thethreshold value x₁ as between times t1 to ta shown in FIG. 6, theprocessing device ends the data analysis process. If the processingdevice 135 determines in S151 that the latest value of the amounts ofiron stored in the hard disk 133 is equal to or larger than thethreshold value x₁ as between times tb to td shown in FIG. 6, theprocessing device determines whether the latest value of the amounts ofiron stored in the hard disk 133 is equal to or larger than a thresholdvalue x₂ (see FIG. 6) or not (S152).

If the processing device 135 determines in S152 that the latest value ofthe amounts of iron stored in the hard disk 133 is smaller than thethreshold value x₂ as in times tb and tc shown in FIG. 6, the processingdevice displays information for prompting the user to prepare forreplacement of the speed reducer 20, as maintenance information on thedisplay 134 (S153), and ends the data analysis process. For example, theinformation for prompting the user to prepare for replacement of thespeed reducer 20 is information for instructing preparation of areplacement speed reducer within two months. In S153, in addition todisplay of the information for prompting the user to prepare forreplacement of the speed reducer 20 on the display 134, the processingdevice 135 may display also information indicating how many days laterthe user preferably performs a series of operations of causing themaintenance information output apparatus 130 to obtain the data of theamount of iron in the lubricant 20 a in the speed reducer 20 from theiron amount detecting device 110 through the portable wireless receiver120 and perform the data analysis process, as maintenance information onthe display 134. If the processing device 135 determines that the latestvalue of the amounts of iron stored in the hard disk 133 is equal to orlarger than the threshold value x₂ as in time td shown in FIG. 6, theprocessing device displays information for prompting the user to replacethe speed reducer 20, as maintenance information on the display 134(S154), and ends the data analysis process.

The processing device 135 is configured so that, after the devicereceives through the wired communicating portion 132 the data of theamount of iron transmitted through the wired communicating portion 123of the portable wireless receiver 120, the device displays the latestvalue of the amounts of iron and a time series on the display 134.Alternatively, the device may be configured so that, when requested bythe user through the operating portion 131, the device displays thelatest value of the amounts of iron and a time series on the display134.

The processing device 135 is configured so that, after the devicereceives through the wired communicating portion 132 the data of theamount of iron transmitted through the wired communicating portion 123of the portable wireless receiver 120, the device performs the dataanalysis process shown in FIG. 7. Alternatively, the device may beconfigured so that, when requested by the user through the operatingportion 131, the device performs data analysis process shown in FIG. 7.

As described above, on the basis of the amount of iron which is actuallyproduced in the lubricant 20 a in the speed reducer 20 as a result ofwear of the speed reducer 20, the maintenance information outputapparatus 130 outputs maintenance information of the speed reducer 20.Therefore, the apparatus can output maintenance information of the speedreducer 20, more adequately than the conventional art.

In the maintenance information output apparatus 130, furthermore,threshold values of plural steps or the threshold values x₁, x₂ aredisposed, and the maintenance information is disposed in plural steps inaccordance with the threshold values x₁, x₂. Therefore, the maintenanceinformation output apparatus can allow the user to perform stepwisemaintenance.

The maintenance information output system 100 is configured so as tooutput maintenance information in the form of display. Alternatively,maintenance information may be output by a method other than display.For example, the maintenance information output system 100 may outputmaintenance information in the form of sound.

In the maintenance information output system 100, the two steps ofthreshold values or the threshold values x₁, x₂ are disposed.Alternatively, three or more steps of threshold values may be disposed.

In the maintenance information output system 100, the communicationbetween the portable wireless receiver 120 and the maintenanceinformation output apparatus 130 is performed by wire. Alternatively,the communication may be performed by wireless.

The maintenance information output system 100 comprises the portablewireless receiver 120 which obtains data of the amounts of iron from theiron amount detecting devices 110, and the maintenance informationoutput apparatus 130 which performs the data analysis process on thebasis of the data of the amounts of iron obtained from the portablewireless receiver 120. Alternatively, a single device may obtain data ofthe amounts of iron from the iron amount detecting devices 110, andperforms the data analysis process.

An eccentric oscillation speed reducer is used as the speed reducer 20.The invention can be applied to any type of speed reducer as far assteel products are used in components of the speed reducer, and thestructure of the speed reducer itself may not be formed as an eccentricoscillation speed reducer. However, it is advantageous to apply theinvention to a speed reducer comprising plural rotation transmittingportions of an industrial robot, because maintenance information ofplural reductions can be simultaneously managed.

In the case of an eccentric oscillation speed reducer which has arelatively complex internal structure and is hardly disassembled,particularly, it is advantageous to apply the invention and to be ableto know necessity/unnecessity of maintenance.

In the above, the description has been made with using the example inwhich the iron amount detecting devices 110 are attached to both themembers 12 a, 12 b that constitute the joint portion of the robot. Theplacement of the iron amount detecting device is not restricted to thatin which the iron amount detecting devices are attached to both themembers that constitute the joint portion. One iron amount detectingdevice may be disposed only on one side. Plural iron amount detectingdevices may be placed on one face and at positions opposed to pluralcrankshafts, respectively. In the above, the example in which the ironamount detecting devices are attached to the members that constitute thejoint portion of the robot has been described. In a speed reducer whichis unitized in a state where components of the speed reducer itself arehoused in a housing or the like and lubricating oil is hermeticallyenclosed, maintenance information can be obtained while an iron amountdetecting device is attached to the housing.

INDUSTRIAL APPLICABILITY

The maintenance information output apparatus and maintenance informationoutput system of the invention output maintenance information of a speedreducer on the basis of the amount of iron which is actually produced inthe lubricant in the speed reducer as a result of wear of the speedreducer. Therefore, the apparatus and the system can output maintenanceinformation of the speed reducer, more adequately than the prior art.Also in the case where the invention is applied to an eccentricoscillation speed reducer, moreover, maintenance information of thespeed reducer can be obtained on the basis of the detected amount ofiron.

We claim:
 1. A maintenance information output system comprising: an ironamount detecting device which is attached to a speed reducer, and whichdetects an amount of iron in a lubricant in the speed reducer; awireless receiver which receives data of the amount of iron detected bythe iron amount detecting device; and a maintenance information outputapparatus including: an outputting portion which outputs maintenanceinformation of the speed reducer, a wired receiving portion whichreceives the data from the wireless receiver, and a controlling portionwhich, when the amount of iron is equal to or larger than a thresholdvalue, causes the outputting portion to output the maintenanceinformation, wherein the controlling portion functions during operationof the speed reducer.